The present invention in one aspect relates to removal of selected gases from the atmosphere. The invention has particular utility in connection with the extraction of carbon dioxide (CO2) from the atmosphere and subsequent sequestration of the extracted CO2 or conversion of the extracted CO2 to useful or benign products and will be described in connection with such utilities, although other utilities are contemplated, including the extraction, sequestration or conversion of other gases from the atmosphere including NOx and SO2.
There is compelling evidence of a strong correlation between the sharply increasing levels of atmospheric CO2 with a commensurate increase in global surface temperatures. This effect is commonly known as Global Warming. Of the various sources of the CO2 emissions, there are a vast number of small, widely distributed emitters that are impractical to mitigate at the source. Additionally, large-scale emitters such as hydrocarbon-fueled power plants are not fully protected from exhausting CO2 into the atmosphere. Combined, these major sources, as well as others, have lead to the creation of a sharply increasing rate of atmospheric CO2 concentration. Until all emitters are corrected at their source, other technologies are required to capture the increasing, albeit relatively low, background levels of atmospheric CO2. Efforts are underway to augment existing emissions reducing technologies as well as the development of new and novel techniques for the direct capture of ambient CO2. These efforts require methodologies to manage the resulting concentrated waste streams of CO2 in such a manner as to prevent its reintroduction to the atmosphere.
The production of CO2 occurs in a variety of industrial applications such as the generation of electricity from coal at power plants and in the use of hydrocarbons that are typically the main components of fuels that are combusted in combustion devices, such as engines. Exhaust gas discharged from such combustion devices contains CO2 gas, which at present is simply released to the atmosphere. However, as greenhouse gas concerns mount, CO2 emissions from all sources will have to be curtailed. For mobile sources such as motor vehicles and airplanes the best option is likely to be the collection of CO2 directly from the air rather than from the mobile device in the motor vehicle or airplane. The advantage of removing CO2 from air is that it eliminates the need for storing CO2 on the mobile device.
Extracting carbon dioxide (CO2) from ambient air would make it possible to use carbon-based fuels and deal with the associated greenhouse gas emissions after the fact. Since CO2 is neither poisonous nor harmful in parts per million quantities, but creates environmental problems simply by accumulating in the atmosphere, it is possible to remove CO2 from air in order to compensate for equally sized emissions elsewhere and at different times.